Method of producing fluids from a well bore producing formation



July 16, 1968 M. L. REED 3,392,783

METHOD OF PRODUCING FLUIDS FROM A WELL BORE PRODUCING FORMATION FiledNOV. 10, 1966 2 Sheets-Sheet 1 5G z wemfi j {AM W40 BY 6,. W

M. L.. REED July 16, 1968 METHOD OF PRODUCING FLUIDS FROM A WELL BOREPRODUCING FORMATION 2 Sheets-Sheet 2 Filed Nov. 10, 1966 STEAM ATTO NE)United States Patent 3,392,783 METHOD OF PRODUCING FLUIDS FROM A WELLBORE PRODUCING FORMATION Milner L. Reed, Houston, Tex., assignor toBrown Oil Tools, Inc., Houston, Tex., a corporation of Texas Filed Nov.10, 1966, Ser. No. 593,502 8 Claims. (Cl. 166-40) The present inventionrelates to an improved method of producing well fluids in which the wellfluids are heated in the producing formation by injection of a heatedfluid from the surface of the well bore.

In the production of low gravity non viscous hydrocarbons from aproducing formation, steam has been injected through a well pipe stringon which a packer is mounted to allow the steam pressure to bemaintained at the face of the particular producing formation beingtreated. It has been a common practice to provide a bypass of the wellpacker which may be opened or closed by manipulation of the well pipe.This control of the bypass requires that some additional equipment, suchas, hoisting equipment be available at the wellhead.

It is therefore an object of the present invention to provide animproved method for producing well fluid with injection of heated fluidin the well which eliminates the need of such well string handlingequipment at the surface of the well bore.

Another object is to provide an improved method of steam injection intoa well bore in which the packer bypass is controlled withoutmanipulation of the well string on which the packer is mounted.

A further object is to provide an improved method of injecting steaminto a well bore producing formation through a well string having a wellpacker mounted thereon and set against the well bore in which the packerbypass is normally open and is closed, responsive to the heat of theinjected steam.

Still another object is to provide an improved method of producing wellfluids from a well bore formation by steam injection under pressure inwhich the normally open well packer by-pass closes during steaminjection and opens thereafter to provide more efiicient pumping of thefluids from the well bore.

These and other objects and advantages of the present invention arehereinafter set forth and explained in relation to the drawings showinga preferred form of the present invention and wherein:

FIGURE 1 is a partial longitudinal sectional view of a well packer inset position which has a by-pass that may be controlled in accordancewith the present invention.

FIGURE 2 is a schematic sectional view of a well bore and illustratingthe position of the well packer by-pass before steam injection andshowing the cleaning of the well.

FIGURE 3 is a similar view illustrating steam injection.

FIGURE 4 is another view similar to FIGURES 2 and 3 which illustratesthe pumping of well fluids after steam injection has been completed.

Referring to the drawings, FIGURE 1 illustrates a well packer suitablefor use with the improved method of the present invention. This wellpacker is disclosed in the application of John B. Davis, Ser. No.553,455, filed May 27, 1966 and entitled Well Packer. This well packeris adapted to be lowered into a well bore on a well string, such astubing string T, and set to seal against the interior of the casing C.This well packer includes inner and outer tubular supports and 12,packing assembly P, anchor- 3,392,783 Patented July 16, 1968 ingassembly A, setting means S and a release means R. Both tubular supports10 and 12 are connected to the collar 14 on tubing string T and arespaced apart to define the passageway 16. The lower end of inner tubularsupport 10 connects to the lower extension of tubing string T. The lowerend of outer tubular support 12 connects to the grooved collar 18 whichcooperates with the pins 20 in the sleeve 22 depending from theanchoring assembly A to prevent inadvertent release of the releasingmeans R except when the packer is to be unset.

The by-pass includes the passageway 16 and the ports 24 defined in outertubular support 12. The interior of the packing assembly P includes theseal 26 which is adapted to seal against the exterior of tubular support12. Thus, when the ports 24 are positioned below the seal 26, theby-pass is closed and when they are positioned above the seal 26, theby-pass is open.

This packer is set by lowering the tubing string T to position the pins28 on collar 14 in the grooves 30 at the upper end of the setting meansS and rotating the tubing string T to cause the setting means S tocompress the packing and anchoring assemblies into set position.Thereafter, the tubing string T may be moved to position the ports 24either above or below the seal 26.

Referring to the schematic illustrations of FIGURES 2, 3 and 4, the wellbore B extends through the producing formation F. The casing C has beenset in the well bore B and extends from the surface down to a levelabove the producing formation F. The well packer has been lowered on thetubing string T and its packing assembly P and anchoring assembly A havebeen set against the interior of the casing C. With the packer set, thetubing string T is supported by the slips 32 in the tubing head assembly34 and the usual packing 36 seals around the tubing string T. A valve 38is installed in the tubing string T above the packing P and suitableconnection (not shown) is provided to the upper end of tubing string Tfor the circulation of fluids thereto. The line 40 controlled by thevalve 42 connects into the upper end of the casing C to control thedischarge of fluids in the annulus defined by the casing C and thetubing string T.

In accordance with the present invention, the positioning of the tubingstring T, when it is supported at the surface, positions the ports 24 apreselected distance above the well packer seal 26 so that the wellpacker by-pass is open. The position of ports 24 is selected to assureclosing of the by-pass by thermal expansion of the tubing string Tduring the initial phases of steam injection. Another factor to considerin positioning the tubing string, is to be sure that sufiicient lengthof the tubular supports 10 and 12 is provided above the well packer toassure that the thermal expansion of the tubing string T does not movethe collar 14 into direct contact with the well packer. Thus, the collar14 should be a sufiicient distance above the well packer so that nothermal expansion forces are exerted on the well packer but rather thetubular supports 10 and 12 slide through the well packer to accommodatethermal expansion of the tubing string T.

With the well packer set and the tubing string T properly positioned asdescribed, fresh water is circulated, as shown by the arrows in FIGURE2, down through the tubing string T and upwardly through the by-pass andthe annulus to discharge mud and oil from the well bore through line 40and to fill both the tubing string and the annulus with fresh water.

Upon completion of Water circulation, steam is injected through thetubing string T with the valve 42 closed.

The steam pressure forces some of the water into the producing formationF. The temperature of the steam injected heats the tubing string Tcausing it to expand downwardly to close the by-pass by moving the ports24 downwardly through the seal 26. As long as the ports 24 are open andthe annulus is full of water, the pressures above and below the wellpacker are equalized and substantially no fluids flow through the ports24. When the by-pass closes, the annulus pressure at the surface startsto build as a result of the heating of the water in the annulus. As soonas this pressure increase is detected, as by a pressure gauge (notshown) in line 40 between valve 42 and the annulus, the valve 42 ispreferably opened to allow the water in the annulus to be vaporized. Itis generally preferred to vaporize the water from the by-pass as a meansof limiting the temperature to which the casing C is heated and to avoidhaving to pump the water from the well bore during the production of thewell fluids from the producing formation F.

With the by-pass closed, the continued injection of steam forces thesteam into the producing formation F and thereby provides the desiredheat in the formation to assist in the recovery of the well fluids fromthe formation/FIGURE 2 illustrates the steam injection step of themethod and shows the by-pass closed and the water vaporized from theannulus above the well packer. Generally, steam injection is continuedfor several days until the desired degree of heating of the producingformation has been achieved.

When the steam injection step is completed, suitable producingequipment, such as the pump shown in FIG- URE 4, is installed in thetubing string T and the Well fluids are allowed to flow into the wellbore B to a level above the lower end of the tubing string T. Duringthis period, the tubing string T is cooling and when cooledsufficiently, contracts to open the by-pass. With the bypass open,vapors in the well bore flow up through the by-pass through the annulusand are discharged through line 40 under control of valve 42.

The well fluids in the well bore are produced upward through the tubingstring T and are directed to suitable surface recovery equipment (notshown) wherein the well fluids and water produced from the well bore maybe readily separated. Production of well fluids is continued so long asthe amount of well fluids recovered justifies.

Generally when the production is stopped, the well is again subjected tosteam injection. To start steam injection, the pumping equipment isremoved from the tubing string T. Steam injection may then beimmediately commenced but it is preferred that the tubing string and theannulus be filled with fresh water before starting the steam injectionto assure that there is substantially no fluid flow through the 'by-passas it is closed. In this manner, the by-pass seal 26 is protected fromthe cutting action of fluids which might exist during closing.

The commencement of steam injection heats the tubing string T causing itto elongate and close the by-pass. The steam injection and production ofwell fluids proceeds as described. The steps of steam injection andproduction of well fluids are continued as long as the well fluidsrecovered justify the expense of the operation.

From the foregoing, it can be seen that the present invention provides amethod of producing well fluids by steam injection which does notrequire manipulation of the tubing string to control the opening andclosing of the well packer by-pass once the tubing string has been hungin its preselected position. This method, therefore, eliminates the needfor hoisting equipment for manipulating the tubing string at thesurface. The by-pass is closed by the thermal expansion of the tubingwhich is heated by the steam.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimsWithoutdeparting from the spirit of the invention.

What is claimed is:

1. The method of heating a producing formation in a well =bore,comprising running into a well bore, a well packer having a packingassembly, a tubular support with a by-pass therethrough and a sealbetween said packing assembly and said tubular support with said wellpacker supported on atubing string, 1 setting said well packer in saidwell bore, e

positioning said tubular support with said by-pass a preselecteddistance above said seal, and" injecting steam through said tubingstring,

said injected steam heating said tubing string and said tubular supportwhereby thermal elongation of said tubing string and said tubularsupport moves said by-pass through said seal and closes thegby-passaround said well packer.

2. The method according to claim .1, includingthe steps of circulatingfresh water through said tubing string into said well bore after saidpacker is set and said tubular support is positioned with respect tosaid seal and prior to said steam injection.

3. The method according to claim 2,v including the steps of j openingthe annulus at the surface surrounding the tubing string during thecirculation of fresh water, and closing said annulus for the injectionof steam. 4. The method according to claim 3, including the steps ofdetecting an increase of pressure in said annulus at the surface duringsteam injection, and

thereafter opening said annulus at the surface to .dis-

charge water vapors which are formed in said annulus by the heating ofthe water therein by the injected steam.

5. The method of producing well fluids from a producing formation in awell bore, comprising running and setting a well packer having a by-passon a tubing string above the producing formation in the well bore,

supporting said tubing string at the wellhead so that the by-pass ofsaid well packer is open,

injecting fresh water to wash the well bore,

injecting steam through said tubing string whereby the tubing stringelongates responsive to a temperature increase and closes said by-pass,

discontinuing steam injection to allow the tubing string to cool wherebyit contracts responsive to the cooling to open said by-pass, and

producing fluids from the producing formation upwardly through thetubing string.

6. The method according to claim 5, wherein the annulus around thetubing string is open at the surface during the injection of fresh waterand including the steps of,

closing said annulus during initial steam injection to minimize flowthrough said by-pass'while' said bypass is closing.

7. The method according to claim 6, including the steps of detecting apressure increase in said annulus during initial steam injection todetect the closing of said by-pass, and

thereafter opening said annulus to discharge vapors therein caused bythe heat of said stream.

8. The method according to claim 5, including the steps of injectingfresh water through said tubing string after said producing step isterminated, and

thereafter repeating the steps of injecting steam, discontinuing steaminjection and producing fluids through the tubing string.

(References on following page) References Cited UNITED STATES PATENTSCrites et a1 16653 X Harlan et a1. 166-39 5 Sutliff et a1. 16640 X Brown16648 6 OTHER REFERENCES Owens, W. D., et aL: Steam Stimulation forSecondary Recovery, in Producers Monthly 29 (4), April 1965, pp. 8 and10-13.

CHARLES E. OCONNELL, Primaly Examiner.

I. A. CALVERT, Assistant Examiner.

1. THE METHOD OF HEATING A PRODUCING FORMATION IN A WELL BORE,COMPRISING RUNNING INTO A WELL BORE, A WELL PACKER HAVING A PACKINGASSEMBLY, A TUBULAR SUPPORT WITH A BY-PASS THERETHROUGH AND A SEALBETWEEN SAID PACKING ASSEMBLY AND SAID TUBULAR SUPPORT WITH SAID WELLPACKER SUPPORTED ON A TUBING STRING, SETTING SAID WELL PACKER IN SAIDWELL BORE, POSITIONING SAID TUBULAR SUPPORT WITH SAID BY-PASS APRESELECTED DISTANCE ABOVE SAID SEAL, AND INJECTING STEAM THROUGH SAIDTUBING STRING, SAID INJECTED STEAM HEATING SAID TUBING STRING AND SAIDTUBULAR SUPPORT WHEREBY THERMAL ELONGATION OF SAID TUBING STRING ANDSAID TUBULAR SUPPORT MOVES SAID BY-PASS THROUGH SAID SEAL AND CLOSES THEBY-PASS AROUND SAID WELL PACKER.